This invention relates in general to computer software, and in particular to a method and system for creating a standard interface which allows two or more systems to be accessed at the same time on the same machine.
Services such as electronic mail, document management, image processing, and fax processing are common software applications available from many different vendors. These applications generally provide a standard graphical interface for general use as well as a programmable interface in order to allow custom applications to make use of the services. Frequently, standards organizations have been formed to create interfaces subject to standard formats to allow customers to write one set of programs that can be used with any of the services that comply therewith. Companies often find, for many valid reasons, that they receive the same service from several different vendors, and at some point they need to interface with more than one of the services at the same time. A classic example of this is a mail gateway that connects two or more distinct mail systems together. Another example is having images stored in Lotus Notes and Visual Info and a need to view images from both systems at the same time as well as exchange data between them. In cases such as these, a standard programmable interface fails because it requires that only one service be available on a machine at any one time (usually because the interface is a Dynamic Link Library (DLL) and the operating systems can only load one of these with the same name at any one time). Thus there needs to be a way to create a standard interface which allows two or more systems to be accessed at the same time on the same machine and in which the program does not need to be changed when later on additional programs are developed that conformed to the same standard or an enhanced version of the standard.
The reasons for this access are for gateway type functions which need to access data spread over services provided by different vendors at the same time. What is needed is an interface with the following features and characteristics:
(1) Ability to write programs that work with any product conforming to the interface with out any vendor specific code needing to be added to the program;
(2) Programs written to the interface can work with more than one product that conforms to the interface at the same time. This should also be simple and straight forward;
(3) Programs that use the interface must continue to function even if new features are added to the interface and must not require recompilation or linking of the old program.
These requirements disqualify the typical model where standard function entry points are defined and each vendor provides a DLL with the same name and entry points. Having each vendor create a DLL with a different name could work, but would require programs to be built for each specific vendor""s product, or the programs would have to dynamically load each DLL and load all of the function points in each of the DLLs and keep track of which set of function points to use. This can be very tedious and error prone.
The present invention relates to a method and system for interfacing, from a single computer, a plurality of applications and services that conform to a standard. An abstract class is created with defined Data Objects and desired functions. For each of the services that will conform to the standard interface, subclasses of the abstract class are then created.